To be completely honest, I dont worry about fragmentation anymore.
My C: is an SSD so even though its quite likely to be ridiculously fragmented, it does not matter a jot, and the D: is my Apps and Games Drive, E: is my Media drive and F: is my junk and everything else drive, and to be honest, I use O&O DeFrag and I have it set to do the Hard Disks once a fortnight and a quick peek showsone or two red dots on the whole lot, so fragmentation is a non issue.
If you are one of those people who likes to throw all their eggs into the one C: basket then you deserve everything thats coming to you, including the reality that the moment you finish defragging C:... It will need defragging soon again LOL
Only joking of course ( NOT! )
But seriously, a drive can get seriously messed up before it makes any actual real world difference... I have taken a piccie of a drive that I was sorting out for a friend, and his C: was actually 103% fragmented??? - 103???? I never thought that was even possible, but yeah, its a sea of red... Now that needed to be defragged, but... Sod it Im waffling.